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Generalise --dhcp-relay.

Browse Source 
Sending via broadcast/multicast is now supported for both
IPv4 and IPv6 and the configuration syntax made
easier (but backwards compatible).
This commit is contained in:
Simon Kelley
2021-12-20 16:40:41 +00:00
parent 1176cd58c9
commit 18b1d1424e
6 changed files with 101 additions and 25 deletions
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18
src/dhcp-common.c
View File

@@ -985,11 +985,27 @@ void log_context(int family, struct dhcp_context *context)
void log_relay(int family, struct dhcp_relay *relay)
{
int broadcast = relay->server.addr4.s_addr == 0;
inet_ntop(family, &relay->local, daemon->addrbuff, ADDRSTRLEN);
inet_ntop(family, &relay->server, daemon->namebuff, ADDRSTRLEN);
#ifdef HAVE_DHCP6
struct in6_addr multicast;
inet_pton(AF_INET6, ALL_SERVERS, &multicast);
if (family == AF_INET6)
broadcast = IN6_ARE_ADDR_EQUAL(&relay->server.addr6, &multicast);
#endif
if (relay->interface)
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay from %s to %s via %s"), daemon->addrbuff, daemon->namebuff, relay->interface);
{
if (broadcast)
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay from %s via %s"), daemon->addrbuff, relay->interface);
else
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay from %s to %s via %s"), daemon->addrbuff, daemon->namebuff, relay->interface);
}
else
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay from %s to %s"), daemon->addrbuff, daemon->namebuff);
}

27
src/dhcp.c
View File

@@ -1095,14 +1095,35 @@ static int relay_upstream4(struct dhcp_relay *relay, struct dhcp_packet *mess,
to.sa.sa_family = AF_INET;
to.in.sin_addr = relay->server.addr4;
to.in.sin_port = htons(daemon->dhcp_server_port);
/* Broadcasting to server. */
if (relay->server.addr4.s_addr == 0)
{
struct ifreq ifr;
if (relay->interface)
safe_strncpy(ifr.ifr_name, relay->interface, IF_NAMESIZE);
if (!relay->interface || strchr(relay->interface, '*') ||
ioctl(daemon->dhcpfd, SIOCGIFBRDADDR, &ifr) == -1)
{
my_syslog(MS_DHCP | LOG_ERR, _("Cannot broadcast DHCP relay via interface %s"), relay->interface);
return 1;
}
to.in.sin_addr = ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr;
}
send_from(daemon->dhcpfd, 0, (char *)mess, sz, &to, &from, 0);
if (option_bool(OPT_LOG_OPTS))
{
inet_ntop(AF_INET, &relay->local, daemon->addrbuff, ADDRSTRLEN);
inet_ntop(AF_INET, &relay->server.addr4, daemon->dhcp_buff2, DHCP_BUFF_SZ);
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay %s -> %s"), daemon->addrbuff, daemon->dhcp_buff2);
if (relay->server.addr4.s_addr == 0)
snprintf(daemon->dhcp_buff2, DHCP_BUFF_SZ, _("broadcast via %s"), relay->interface);
else
inet_ntop(AF_INET, &relay->server.addr4, daemon->dhcp_buff2, DHCP_BUFF_SZ);
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay at %s -> %s"), daemon->addrbuff, daemon->dhcp_buff2);
}
/* Save this for replies */

56
src/option.c
View File

@@ -4281,26 +4281,56 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
}
}
break;
case LOPT_RELAY: /* --dhcp-relay */
{
struct dhcp_relay *new = opt_malloc(sizeof(struct dhcp_relay));
comma = split(arg);
new->interface = opt_string_alloc(split(comma));
char *two = split(arg);
char *three = split(two);
new->iface_index = 0;
if (comma && inet_pton(AF_INET, arg, &new->local) && inet_pton(AF_INET, comma, &new->server))
if (two)
{
new->next = daemon->relay4;
daemon->relay4 = new;
}
if (inet_pton(AF_INET, arg, &new->local))
{
if (!inet_pton(AF_INET, two, &new->server))
{
new->server.addr4.s_addr = 0;
/* Fail for three arg version where there are not two addresses.
Also fail when broadcasting to wildcard address. */
if (three || strchr(two, '*'))
two = NULL;
else
three = two;
}
new->next = daemon->relay4;
daemon->relay4 = new;
}
#ifdef HAVE_DHCP6
else if (comma && inet_pton(AF_INET6, arg, &new->local) && inet_pton(AF_INET6, comma, &new->server))
{
new->next = daemon->relay6;
daemon->relay6 = new;
}
else if (inet_pton(AF_INET6, arg, &new->local))
{
if (!inet_pton(AF_INET6, two, &new->server))
{
inet_pton(AF_INET6, ALL_SERVERS, &new->server.addr6);
/* Fail for three arg version where there are not two addresses.
Also fail when multicasting to wildcard address. */
if (three || strchr(two, '*'))
two = NULL;
else
three = two;
}
new->next = daemon->relay6;
daemon->relay6 = new;
}
#endif
else
new->interface = opt_string_alloc(three);
}
if (!two)
{
free(new->interface);
ret_err_free(_("Bad dhcp-relay"), new);

12
src/rfc3315.c
View File

@@ -2170,7 +2170,10 @@ void relay_upstream6(struct dhcp_relay *relay, ssize_t sz,
if (!relay->interface || strchr(relay->interface, '*') ||
(multicast_iface = if_nametoindex(relay->interface)) == 0 ||
setsockopt(daemon->dhcp6fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &multicast_iface, sizeof(multicast_iface)) == -1)
my_syslog(MS_DHCP | LOG_ERR, _("Cannot multicast to DHCPv6 server without correct interface"));
{
my_syslog(MS_DHCP | LOG_ERR, _("Cannot multicast DHCP relay via interface %s"), relay->interface);
return;
}
}
send_from(daemon->dhcp6fd, 0, daemon->outpacket.iov_base, save_counter(-1), &to, &from, 0);
@@ -2178,8 +2181,11 @@ void relay_upstream6(struct dhcp_relay *relay, ssize_t sz,
if (option_bool(OPT_LOG_OPTS))
{
inet_ntop(AF_INET6, &relay->local, daemon->addrbuff, ADDRSTRLEN);
inet_ntop(AF_INET6, &relay->server, daemon->namebuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay %s -> %s"), daemon->addrbuff, daemon->namebuff);
if (IN6_ARE_ADDR_EQUAL(&relay->server.addr6, &multicast))
snprintf(daemon->namebuff, MAXDNAME, _("multicast via %s"), relay->interface);
else
inet_ntop(AF_INET6, &relay->server, daemon->namebuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_INFO, _("DHCP relay at %s -> %s"), daemon->addrbuff, daemon->namebuff);
}
/* Save this for replies */